L17 Photosynthesis II

L17 Photosynthesis II - ReviewofLecture16...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon
Review of Lecture 16 Photosynthesis I: Chapter 8 1. Two Series of Reactions 2. Pigments and the visible spectrum 3. The Photosystems 4. Other Photosystems 5. The Z-scheme 6. Chemiosmosis
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Photosynthesis Two series of reactions: light and dark  (dark reaction is also called the  Calvin cycle) Chap.8, pg. 178
Background image of page 2
The Photosystems 1. Each photosystem is a light-harvesting  complex 2. Consists of a reaction centre and  antenna pigment molecules that transfer  light energy (by RET) to the chlorophyll  a molecule in the reaction centre 3. Light energy causes an electron to be  ejected from the chlorophyll a molecule  in the reaction centre  4. The electron is then transferred to an  acceptor
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The Solar Cell 1. Light strikes the cell and frees an  electron 2. The electron moves toward the  positive charge in the N-layer  3. A second electron replaces it (current  flows) - - - Electron flow positive terminal
Background image of page 4
Movement of electrons in the light reactions Chap.8, pg.183 PQ:plastiquinone, PC:plastocyanin, Fd: ferredoxin
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Chemiosmosis: Chemical Push Chap.8, pg.184
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Independence of Photosystem I 1. Photosystem I  can work independent  of photosystem  II 1. Energized electrons are transferred  from  P 700  and shunted to an electron  acceptor between PII and PI 2. Electrons pass back down to photosystem  I driving H +  transport across the  thylakoid membrane, making more ATP  (no oxygen or NADPH is formed)  3. This process is called ‘ cyclic electron flow’ ferredoxin Primitive photosynthetic mechanism
Background image of page 8
The challenges 1. Harvesting light energy 2. Staying wet when things get dry 3. Dealing with gravity 4. Divide or be conquered  5. Leveraging resources
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Lecture 17 Outline Photosynthesis II: Chapter 8 1. The Calvin Cycle (the dark reactions) 2. Efficiency of carbon fixation 3. Photorespiration 4. The C 4  pathway 5. CAM plants
Background image of page 10
The Calvin Cycle 1. Light reactions use light energy and H 2 O to yield  chemical energy in the form of ATP and NADPH 2. ATP and NADPH fuel the second part of  photosynthesis (the Calvin Cycle) which makes  simple sugar phosphates  3. This is also called the ‘dark reaction’ because it can  take place in the dark 4. Takes place in the  stroma , outside of the  thylakoids
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The Calvin Cycle Chap.8, pg.178
Background image of page 12
The Calvin Cycle 1. Named after Melvin Calvin (together with his  graduate students, Andrew Benson and James  Bassham) who in 1953 determined the pathway by  which plants convert CO 2  into sugars 2. Calvin won the Nobel Prize in 1961 for his  discovery 3. Photosynthetic algae were exposed to radioactive  CO 2  to trace the synthesis of radioactive  compounds 
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Calvin’s Experimental Set up The Lollipop Apparatus Light source Algae alcohol 14 CO 2
Background image of page 14
Image of page 15
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 46

L17 Photosynthesis II - ReviewofLecture16...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online